Changes in size and sonographic characteristics of the adrenal glands during the first year of life and the sonographic diagnosis of adrenal hyperplasia in infants with 21-hydroxylase deficiency.

The sonographic representation of developmental changes occurring in the normal adrenal gland during the first year of life was examined in 84 healthy newborns and infants. As a measure of adrenal size we chose a defined part of standardized adrenal sections, the adrenal size index (ASI). In newborns, ASI was high and decreased during the first year of life. Three different echo types were delineated, each one being predominant in a defined age group. ASI was markedly elevated in 5 patients with the salt-wasting variety of 21-hydroxylase deficiency, whereas in 3 patients without a severe salt loss, ASI was in the upper normal range. Although adrenal enlargement due to salt-wasting 21-hydroxylase deficiency can be recognized by determining ASI, other forms of 21-hydroxylase deficiency do exist in which adrenal enlargement, detectable by ASI measurements, may not be present.